Vehicle wheel serves as an important outer part of automobiles, its visual effects have been continuously improved. In many product categories, finish turning type products have often been preferred, but the processing difficulty of finish turning products is quite large, especially that it is now not automatically processed in current industry. As in general automated processing, manipulators both clamp the front rim section of the wheel, the front side of the finish turning product is not allowed to be touched again after being processed, such that the manipulators have to clamp the lower end of the rim in the finish turning type products automation processing. In order to change the type of the wheel without altering the operation program of a robot, therefore, the manipulators are required at every clamping time that the lower end face of the wheel must be positioned on the fixed height, and the valve hole position can be identified, so as to achieve height measurement of the end face inside the machine after mounting and clamping. Based on the above situations, the present device works well to solve those.